rocker arm off-center to valve stem

[mcjweller]

I'm building a 1776 and have seen a lot of great articles/posts on setting up valve geometry. I don't know if I am lucky but, it seems to be in the middle and level with the top of the valve stem on all the valves at exactly half lift without shims, after having set the valve lash at .006" on them all. I was expecting to have to get some shims or even pushrods with new cylinders, case, heads and 0.030 spacers at the bottom of the cylinders. I got lucky?

My question though is on the rocker arms themselves. It seems all of them on both sides of the engine contact the valve stems off-center by about 1.5MM Below are some pics of the contact line after rotating the motor several times. One of my manuals has a pic and their rockers look slightly off-center from the valves also. I see no adjustment built into the rocker shaft to correct.

Normal? does this off-set encourage the valve to rotate to reduce wear?

Below are a couple pics of the contact zone and one pic showing the valve geometry at half-lift...unfortunately the lube makes it a little hard to see.

[NJ John]

Get solid rocker shafts. They come with washers to move the rockers from side to side. Plus you would lose the clips and wave washers that can fail, if your spinning some RPM.
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[mcjweller]

Thanks NJ John...

I appreciate the suggestion but I'm not going to be buying that set-up. This thing will never see RPM's and, truthfully, the motor is over-budget and well over time.

What I really need is an understanding of why they are offset...which seems to be deliberate looking at the set-up and looking at others as well...as I would like to understand the design intent behind it.

***edit*** I just looked up the EMPI solid rocker shaft kit installation directions. They want the contact with the valves to be offset .015 to .020 "to reduce wear and extend life" or similar wording...which is exactly what I have naturally in this factory setup. So I guess that's my answer, I have to assume the offset spins the valves similar to how cam lobe offset spins lifters/pushrods.

[Dougy Dee]

I see you sorted it out but YES answers your 3 questions in your original post..

[mcjweller]

Thanks Dougy Dee!

[nsracing]

It is offset to facilitate valve stem rotations. This way the valve head will seal and maintain concentric. Valve and seat.

If it stays in one spot it will wear a different shape...not round.

[my3bugs]

i think nsracings got it !!!